JP2022052227A - Receptacle member for multilayer joint, multilayer joint and piping system - Google Patents

Abstract

To provide a receptacle member for a multilayer joint which can enhance cutoff performance, a multilayer joint and a piping system.SOLUTION: In a receptacle member 20 for a multilayer joint having a cylindrical flank part 21 and a circular disc part 23 hanging out of one opening end 22a of the flank part 21, a cutoff protrusion 24 or a cutoff recess 25 is formed at an external face of the circular disc part 23, one or two or more fitting protrusions 26 or fitting recesses 27 are formed at an external face of the flank part 21, and a gate mark G is formed at the flank part 21 at the circular disc part 23 side rather than a center point M of a length of the flank part 21 in a pipe axis O2 direction, and at the other opening end 22b side of the flank part 21 rather than the fitting protrusion 26a which is most approximate to the circular disc part 23, or the fitting recess 27a which is most approximate to the circular disc part 23.SELECTED DRAWING: Figure 2

Description

The present invention relates to a receiving member for a multi-layer joint, a multi-layer joint and a piping system.

Conventionally, a single-layer resin joint formed by injection molding a single resin has been used for connecting resin pipes and the like. As the resin joint, a multi-layer joint having an inner layer and an outer layer using different types of resin materials is known for the purpose of imparting various functions.
For example, Patent Document 1 proposes a multi-layer joint in which a resin material that can be adhesively bonded to a resin pipe member is used for the inner layer and a resin material that can absorb the thermal stretching stress of the resin pipe member is used for the outer layer. Has been done. According to the multi-layer joint of Patent Document 1, the fatigue fracture resistance is improved by thermal expansion and contraction.

Japanese Unexamined Patent Publication No. 2011-002012

The multi-layer joint described in Patent Document 1 can be manufactured by insert molding. In insert molding, the receiving member to be the inner layer is molded in advance, the molded receiving member is fitted into the core of the mold, and then the resin material of the receiving portion to be the outer layer is injected around the receiving member to receive the receiving member. The mouth member and the receiving portion are integrated.

However, when molding the receiving portion, the pre-molded receiving member may be deformed by heating. When the receiving port member is deformed, a gap is created between the receiving port member and the receiving portion, and water infiltrates into this gap, and the water stopping property is lowered.

The present invention has been made in view of such problems, and an object of the present invention is a multi-layer joint receiving member, a multi-layer joint, and a piping system capable of enhancing water stopping.

The present invention has the following aspects.
[1] It has a cylindrical body portion and an annular portion projecting inward from one open end of the body portion, and a water-stopping convex portion or a water-stopping concave portion is formed on the outer surface of the annular portion. , One or more fitting protrusions or fitting recesses are formed on the outer surface of the body, and the annulus is formed on the body from the midpoint of the length of the body in the pipe axis direction. A gate mark is formed on the portion side and on the other open end side of the body portion than the fitting convex portion closest to the annulus portion or the fitting concave portion closest to the annulus portion. , Receptacle member for multi-layer joints.
[2] Formed from a resin containing at least one selected from a hard vinyl chloride resin, an ABS (acrylonitrile-butadiene-styrene copolymer) resin, an acrylic resin, a polycarbonate resin, a polyethylene terephthalate resin, and a urethane resin. The receiving member for a multi-layer joint according to [1].

[3] A tubular joint body having a flow path inside and two or more receiving portions surrounding an opening of the joint main body, and a main body resin forming the joint main body is a receiving portion of the receiving portion. A multi-layer joint in which an outer layer is formed and the receiving member for a multi-layer joint according to [1] or [2] forms an inner layer of the receiving portion of the receiving portion.
[4] The multilayer joint according to [3], wherein the main body resin contains at least one selected from a fluororesin, a polyphenylsulfone resin, a polyphenylene sulfide resin, and an olefin resin.

[5] A piping system including the multi-layer joint according to [3] or [4] and a pipe arranged inside the receiving portion, wherein the pipe is a pipe inner layer facing the flow path. The inner layer of the pipe is formed of a resin containing at least one selected from a fluorine-based resin, a polyphenylsulfone-based resin, a polyphenylene sulfide-based resin, and an olefin-based resin. , The piping outer layer contains a vinyl chloride resin, the end surface of the piping is in contact with the annular portion, and the piping outer layer is in contact with the inner surface of the multi-layer joint receiving member. ..

According to the receiving member for a multi-layer joint of the present invention, the water stopping property can be enhanced.

It is a perspective view of the multilayer joint which concerns on one Embodiment of this invention. It is a perspective view of the receiving member for a multilayer joint which concerns on one Embodiment of this invention. It is a partial cross-sectional view which expanded the region C of FIG. It is a perspective view of the receiving member for a multi-layer joint which shows the relationship between the position of the gate mark of the receiving member for a multi-layer joint and the position of a weld line which concerns on another embodiment of this invention. It is a perspective view of the multi-layer joint receiving member which shows the relationship between the position of the gate mark of the multi-layer joint receiving member which concerns on one comparative example, and the position of a weld line. It is a perspective view of the receiving member for a multi-layer joint which shows the relationship between the position of the gate mark of the receiving member for a multi-layer joint and the position of a weld line which concerns on another comparative example. It is a partial cross-sectional view of the piping system which concerns on one Embodiment of this invention. It is a partial cross-sectional view of the piping system which concerns on one comparative example.

Hereinafter, an embodiment of the multilayer joint according to the present invention will be described with reference to FIG.
As shown in FIG. 1, the multilayer joint 1 of the present embodiment is a straight pipe joint called a socket. The multi-layer joint 1 is cylindrical and has openings 14A and 14B at both ends. The multi-layer joint 1 has a tubular joint body 10 having a flow path 15 inside, and two receiving portions 12A and 12B surrounding the openings 11A and 11B of the joint body 10. The receiving portions 12A and 12B are integrally provided with a receiving member 20 for a multi-layer joint. The main body resin forming the joint main body 10 forms the receiving outer layers 16A and 16B of the receiving portions 12A and 12B. The receiving member 20 for a multi-layer joint forms the receiving inner layers 17A and 17B of the receiving portions 12A and 12B.
The multi-layer joint 1 is, for example, an insert molded product, and the joint main body 10 is made of a single resin (main body resin). In the receiving portions 12A and 12B, the layers formed by the receiving member 20 for the multilayer joint are referred to as the receiving inner layers 17A and 17B, and the layers formed by the main body resin are referred to as the receiving outer layers 16A and 16B.

The multilayer joint 1 has a stepped portion 13A protruding toward the flow path 15 at the boundary between the joint main body 10 and the receiving portion 12A when viewed from the opening portion 14A of the receiving portion 12A. The multilayer joint 1 has a stepped portion 13B protruding toward the flow path 15 at the boundary between the joint main body 10 and the receiving portion 12B when viewed from the opening portion 14B of the receiving portion 12B.
The pipe shaft O1 of the multi-layer joint 1 extends from the opening 14A of the receiving portion 12A toward the opening 14B of the receiving portion 12B. The pipe shafts of the receiving portions 12A and 12B coincide with the pipe shaft O1 of the multilayer joint 1.

As shown in FIG. 2, the multi-layer joint receiving member 20 has a cylindrical body portion 21 and an annular portion 23 projecting inward from one open end 22a of the body portion 21. The annular portion 23 is located at the boundary between the joint main body 10 and the receiving portions 12A and 12B, and forms the surface of the step portion 13A or 13B of the multilayer joint 1. The receiving member 20 for a multi-layer joint has a pipe shaft O2. The tube shaft O2 extends from one open end 22a of the body portion 21 toward the other open end 22b.

A water-stopping convex portion 24 and a water-stopping concave portion 25 are formed on the outer surface of the annular portion 23. The water stop convex portion 24 orbits the opening of the annular portion 23. The water stop concave portion 25 orbits the outer edge of the water stop convex portion 24.
When forming the multi-layer joint 1, the water-stopping convex portion 24 bites into the main body resin, and the main body resin enters the water-stopping recess 25, so that the water flowing through the flow path 15 is formed between the annular portion 23 and the main body resin. It can be prevented from invading the boundary.

Two or more fitting convex portions 26 and two or more fitting concave portions 27 are formed on the outer surface of the body portion 21. The fitting convex portion 26 orbits the outer surface of the body portion 21. The fitting recess 27 orbits the outer surface of the body portion 21. The fitting convex portion closest to the annular portion 23 is referred to as a fitting convex portion 26a. The fitting recess closest to the annulus 23 is referred to as the fitting recess 27a.
A gate mark G, which is a mark of the resin injection part, is formed on the outer surface of the body portion 21. The gate mark G is on the annular portion ₂₃ side of the midpoint M of the length L20 in the pipe axis O2 direction of the body portion 21, and is on the body portion 21 rather than the fitting convex portion 26a or the fitting concave portion 27a. It is formed on the other opening end 22b side.
The position where the gate mark G is formed will be described with reference to FIG.

FIG. 3 is an enlarged partial cross-sectional view of the region C in FIG.
As shown in FIG. 3, in the receiving portion 12A, the main body resin forming the joint main body 10 forms the receiving port outer layer 16A. The receiving member 20 for a multi-layer joint forms the receiving inner layer 17A of the receiving portion 12A. The annulus portion 23 is in contact with the main body resin. The inner surface of the body portion 21 forms the inner surface of the receiving portion 12A. The outer surface of the body portion 21 is in contact with the main body resin. Four fitting protrusions 26a, 26b, 26c, 26d and four fitting recesses 27a, 27b, 27c, 27d are formed on the outer surface of the body portion 21.
The gate mark G is formed at the position of the fitting recess 27b, which is the second closest to the annular portion 23. The boundary between the fitting recess 27a closest to the annular portion 23 and the fitting convex portion 26a closest to the annular portion 23 is K. Assuming that the region between the boundary K and the midpoint M is S, the gate mark G is formed in the region S.

Assuming that the length of the region _S in the pipe axis O2 direction is LS, the distance LG from the boundary K at the position where the gate mark _G is formed is preferably 90% or less, more preferably 70% or less of _LS . 50% or less is more preferable. When the distance _LG is not more than the above upper limit value, the water stoppage of the multi-layer joint 1 can be further enhanced as described later. The smaller the distance _LG is, the more preferable it is, and the lower limit is more than 0% of the length _LS , for example, 1% of the length _LS .

The diameter R ₂₀ of the multi-layer joint receiving member 20 is appropriately determined according to the application of the multi-layer joint 1, and is, for example, preferably 20 to 300 mm, more preferably 30 to 200 mm, still more preferably 40 to 100 mm. When the diameter R ₂₀ of the multi-layer joint receiving member 20 is at least the above lower limit value, it is easy to form integrally with the receiving portion 12A or 12B. When the diameter R ₂₀ of the multi-layer joint receiving member 20 is not more than the above upper limit value, the strength of the multi-layer joint receiving member 20 can be further increased.
The diameter R ₂₀ of the multi-layer joint receiving member 20 refers to the inner diameter of the opening on the other opening end 22b side of the body portion 21.

The length L ₂₀ of the body portion 21 in the pipe axis O2 direction is appropriately determined according to the application of the multilayer joint 1, and is, for example, preferably 10 to 100 mm, more preferably 20 to 80 mm, still more preferably 30 to 60 mm. When the length L ₂₀ of the body portion 21 in the pipe axis O2 direction is at least the above lower limit value, the joint strength with the pipe can be further increased. When the length L ₂₀ of the body portion 21 in the pipe axis O2 direction is not more than the above upper limit value, the strength of the multi-layer joint receiving member 20 can be further increased.

The wall thickness T ₂₀ of the multi-layer joint receiving member 20 is appropriately determined according to the application of the multi-layer joint 1, and is, for example, preferably 1.0 to 30 mm, more preferably 1.5 to 20 mm, and 2.0 to 10 mm. Is more preferable. When the wall thickness T ₂₀ of the multi-layer joint receiving member 20 is at least the above lower limit value, the strength of the multi-layer joint receiving member 20 can be further increased. When the wall thickness T ₂₀ of the multi-layer joint receiving member 20 is not more than the above upper limit value, the multi-layer joint receiving member 20 can be made lighter.
In addition, in this specification, "thickness" means the thickness (minimum wall thickness) at the thinnest position of the member.

The width L ₂₃ of the annular portion 23 of the multi-layer joint receiving member 20 is appropriately determined according to the application of the multi-layer joint 1, and is, for example, preferably 1 to 20 mm, more preferably 2 to 15 mm, and further preferably 3 to 10 mm. preferable. When the width L ₂₃ of the annular portion 23 of the multi-layer joint receiving member 20 is at least the above lower limit value, the water stoppage of the multi-layer joint 1 can be further enhanced. When the width L ₂₃ of the annular portion 23 of the multi-layer joint receiving member 20 is not more than the above upper limit value, the strength of the multi-layer joint receiving member 20 can be further increased.
The width L ₂₃ of the annulus portion 23 means the width from the inner surface of the body portion 21.

The wall thickness T ₂₃ of the annulus portion 23 is appropriately determined according to the use of the multi-layer joint 1, and is preferably 1 to 20 mm, more preferably 2 to 15 mm, still more preferably 3 to 10 mm, for example. When the wall thickness T ₂₃ of the annulus portion 23 is at least the above lower limit value, the strength of the annulus portion 23 can be further increased. When the wall thickness T ₂₃ of the annular portion 23 is not more than the above upper limit value, the multi-layer joint receiving member 20 can be made lighter.

The length L ₁₀ of the joint body 10 of the multi-layer joint 1 in the pipe axis O1 direction is appropriately determined according to the application of the multi-layer joint 1, and is, for example, preferably 20 to 500 mm, more preferably 30 to 400 mm, and 40 to 300 mm. More preferred. When the length L ₁₀ of the joint body 10 in the pipe axis O1 direction is at least the above lower limit value, the joint body 10 can be easily formed. When the length L ₁₀ of the joint body 10 in the pipe axis O1 direction is not more than the above upper limit value, the strength of the multi-layer joint 1 can be further increased.

The length L _12A of the receiving portion 12A of the multi-layer joint 1 in the pipe axis O1 direction is the same as the length L ₂₀ of the body portion 21 of the receiving member 20 for the multi-layer joint in the pipe axis O2 direction.
The length L _12B of the receiving portion 12B of the multi-layer joint 1 in the pipe axis O1 direction is the same as the length L ₂₀ of the body portion 21 of the receiving member 20 for the multi-layer joint in the pipe axis O2 direction.

The wall thickness T ₁₀ of the joint body 10 is appropriately determined according to the use of the multi-layer joint 1, and is preferably 2 to 40 mm, more preferably 3 to 30 mm, still more preferably 4 to 20 mm, for example. When the wall thickness T ₁₀ of the joint body 10 is at least the above lower limit value, the strength of the multi-layer joint 1 can be further increased. When the wall thickness T ₁₀ of the joint main body 10 is not more than the above upper limit value, the amount of the main body resin used can be saved.

The wall thickness T _16A of the socket outer layer 16A is appropriately determined according to the application of the multilayer joint 1, and is, for example, preferably 2.0 to 30 mm, more preferably 2.5 to 20 mm, still more preferably 3.0 to 15 mm. .. When the wall thickness T _16A of the socket outer layer 16A is at least the above lower limit value, the strength of the socket portion 12A can be further increased. When the wall thickness T _16A of the socket outer layer 16A is not more than the above upper limit value, the amount of the main body resin used can be saved.
The wall thickness T _16B of the socket outer layer 16B is the same as the wall thickness T _16A of the socket outer layer 16A.

The height H _13A of the step portion 13A is appropriately determined according to the application of the multilayer joint 1, and is preferably, for example, 3 to 50 mm, more preferably 5 to 40 mm, still more preferably 10 to 30 mm. When the height H _13A of the step portion 13A is at least the above lower limit value, it is easy to fix the pipe. When the height H _13A of the step portion 13A is not more than the above upper limit value, the strength of the receiving portion 12A can be further increased.
The height H _13A of the step portion 13A refers to the height from the outer surface of the joint body 10 to the outer surface of the receiving portion 12A.
The height of the step portion 13B is the same as the height H _13A of the step portion 13A.

The receiving member 20 for a multi-layer joint is made of resin. Examples of the resin forming the receiving member 20 for the multilayer joint include a hard vinyl chloride resin, an ABS (acrylonitrile-butadiene-styrene copolymer) resin, an acrylic resin, a polycarbonate resin, a polyethylene terephthalate resin, and a urethane resin. Can be mentioned. As the resin forming the receiving member 20 for the multilayer joint, a rigid vinyl chloride resin, an ABS resin, and an acrylic resin are preferable, and a rigid vinyl chloride resin and an ABS resin are preferable because deformation due to heating during insert molding is unlikely to occur. Is more preferable.
As the resin forming the receiving member 20 for the multi-layer joint, one type may be used alone, or two or more types may be used in combination.

The receiving member 20 for a multi-layer joint is manufactured by injection molding. At the time of injection molding, the first resin composition which is a raw material of the receiving member 20 for a multi-layer joint is injected into a mold from a resin injection portion (gate). The first resin composition flows in the mold and associates at the farthest position from the gate to form a weld line. The weld line is a portion where the resin composition is associated after the coldest, and the strength is weaker than that of other regions. If the resin composition of the main body resin forming the joint main body 10 and the socket outer layers 16A and 16B comes into contact with the weld line during insert molding, deformation or cracking may occur due to heat. Therefore, if the weld line is located near the annular portion 23, a gap is formed at the boundary between the annular portion 23 and the main body resin, and water may leak from this gap to reduce the water stopping property.
In the present invention, the weld line is moved away from the annulus portion 23 to improve the water stopping property of the multi-layer joint 1. Hereinafter, the relationship between the position of the gate mark and the position of the weld line will be described with reference to the drawings.

FIG. 4 is a perspective view showing the relationship between the position of the gate mark of the multi-layer joint receiving member 20a and the position of the weld line. The multi-layer joint receiving member 20a has the same configuration as the multi-layer joint receiving member 20 except that the positions of the gate marks are different. In FIG. 4, the gate mark G1 is located near one open end 22a of the multi-layer joint receiving member 20a. The first resin composition injected into the mold from the gate at the position corresponding to the gate mark G1 flows in the direction of the arrow F1 and associates at the position farthest from the gate mark G1 to form the weld line WL1. Ru. The weld line WL1 is formed at a position close to the other open end 22b of the multi-layer joint receiving member 20a. Therefore, even if the weld line WL1 is deformed or cracked due to heat, water leakage from the boundary between the annular portion 23 and the main body resin can be suppressed, and the water stoppage can be enhanced.

As shown in FIG. 5, in the multi-layer joint receiving member 20b, the position of the gate mark G2 is at the position of the midpoint M in the pipe axis O2 direction of the body portion 21. The multi-layer joint receiving member 20b has the same configuration as the multi-layer joint receiving member 20 except that the positions of the gate marks are different. The first resin composition injected into the mold from the gate at the position corresponding to the gate mark G2 flows in the direction of the arrow F2a and associates at the position farthest from the gate mark G2 to form the weld line WL2a. Ru. Further, the first resin composition injected into the mold from the gate at the position corresponding to the gate mark G2 flows in the direction of the arrow F2b, meets at the position farthest from the gate mark G2, and the weld line WL2b is formed. It is formed. The weld line WL2a is formed at a position close to one open end 22a of the multi-layer joint receiving member 20b (that is, in the vicinity of the annular portion 23). The weld line WL2b is formed at a position close to the other open end 22b of the multi-layer joint receiving member 20b. If only the weld line WL2b is formed, water leakage from the boundary between the annular portion 23 and the main body resin can be suppressed, and the water stoppage can be enhanced. However, since the weld line WL2a is formed in the multi-layer joint receiving member 20b, water may leak from the boundary between the annular portion 23 and the main body resin, resulting in a decrease in water stopping property. Therefore, it is preferable that the position of the gate mark G2 is not near the midpoint M in the pipe axis O2 direction of the body portion 21.

As shown in FIG. 6, in the multi-layer joint receiving member 20c, the position of the gate mark G3 is close to the other opening end 22b of the body portion 21. The multi-layer joint receiving member 20c has the same configuration as the multi-layer joint receiving member 20 except that the positions of the gate marks are different. The first resin composition injected into the mold from the gate at the position corresponding to the gate mark G3 flows in the direction of the arrow F3 and associates at the position farthest from the gate mark G3 to form the weld line WL3. Ru. The weld line WL3 is formed at a position close to one open end 22a of the multi-layer joint receiving member 20c (that is, in the vicinity of the annular portion 23). Therefore, water may leak from the boundary between the annular portion 23 and the main body resin, and the water stopping property may be lowered. Therefore, it is preferable that the position of the gate mark G3 is not close to the other opening end 22b of the body portion 21.

Next, the flow of the resin composition of the main body resin forming the joint main body 10 at the time of insert molding will be described.
FIG. 7 is a partial cross-sectional view of the vicinity of the receiving portion 12A in the piping system 100.
As shown in FIG. 7, the piping system 100 of the present invention has a multi-layer joint 1, a multi-layer joint receiving member 20, and a pipe 30. In FIG. 7, the multi-layer joint receiving member 20 is fitted to the receiving outer layer 16A of the receiving portion 12A via the fitting convex portions 26a, 26b, 26c, 26d and the fitting recesses 27a, 27b, 27c, 27d. It fits. The pipe 30 is arranged inside the receiving portion 12A. Water (drainage) flows through the flow path of the pipe 30 and the flow path 15 of the multilayer joint 1. In the vicinity of the step portion 13A, the water stop convex portion 24 bites into the main body resin, and the main body resin enters the water stop recess 25, so that the water flowing through the flow path 15 is the boundary between the annular portion 23 and the main body resin. Can be prevented from invading.

At the time of insert molding, the resin composition of the main body resin flows from the side of the joint main body 10 to the side of the opening 14A of the receiving portion 12A. The arrow F indicates the flow direction of the resin composition of the main body resin. In the vicinity of the step portion 13A, the resin composition of the main body resin flowing toward the opening portion 14A of the receiving portion 12A is flowing at a high temperature (for example, 100 to 180 ° C.). Therefore, in the stepped portion 13A, the waterproof convex portion 24 and the waterproof concave portion 25 are exposed to heat, and the multi-layer joint receiving member 20 is easily affected by heating. The receiving member 20 for a multi-layer joint is a fitting convex portion 26a or a fitting convex portion 26a that is closer to the annular portion 23 and is closer to the annular portion ₂₃ than the midpoint M of the length L20 in the pipe axis O2 direction of the body portion 21. A gate mark G is provided on the other open end 22b side of the body portion 21 with respect to the fitting recess 27a closest to the ring portion 23. Therefore, the weld line of the multi-layer joint receiving member 20 is formed on the side of the other open end 22b away from the annular portion 23. Therefore, the multi-layer joint 1 can suppress water leakage from the boundary between the annular portion 23 and the main body resin due to deformation or cracking of the weld line, and can improve water stoppage.
When the gate mark G is formed in the fitting concave portion 27a closest to the annular portion 23 or the fitting convex portion 26a closest to the annular portion 23, a gap is formed at the boundary between the annular portion 23 and the main body resin. It is easy for water in the flow path 15 to infiltrate, and the water stoppage is lowered. Therefore, the gate mark G may be formed on the other open end 22b side of the body portion 21 with respect to the fitting concave portion 27a closest to the annular portion 23 or the fitting convex portion 26a closest to the annular portion 23. preferable.

On the other hand, as shown in FIG. 8, when the gate mark G is the receiving member 20c for a multi-layer joint on the side of the other open end 22b of the body portion 21 (this piping system is 100b and the multi-layer joint is 1b). ), The weld line is formed at a position close to one open end 22a of the body portion 21. Therefore, when the weld line is deformed or cracked due to heating, water in the flow path 15 infiltrates from the boundary between the annular portion 23 and the main body resin, and the inlet inner layer 17A and the receptacle outer layer 16A of the receiving portion 12A enter. A water path 40 is formed at the interface with the water, and water leakage occurs. Therefore, it is preferable that the gate mark G is formed on the ring portion ₂₃ side of the midpoint M of the length L20 in the pipe axis O2 direction of the body portion 21.

The position of the gate mark G can be adjusted by the position of the gate provided in the mold when molding the multi-layer joint receiving member 20.

The joint body 10 and the socket outer layers 16A and 16B are made of resin. Examples of the resin (that is, the main body resin) forming the joint main body 10 and the socket outer layers 16A and 16B include a fluorine-based resin, a polyphenylsulfone-based resin, a polyphenylene sulfide-based resin, and an olefin-based resin. As the main body resin, a fluorine-based resin and a polyphenylsulfone-based resin are preferable from the viewpoint of excellent impact resistance and chemical resistance.
As the main body resin, one type may be used alone, or two or more types may be used in combination.

The pipe 30 preferably has at least an inner layer 31 of the pipe facing the flow path and an outer layer 32 of the pipe located on the outer surface. Since the pipe 30 has the pipe inner layer 31 and the pipe outer layer 32, various functions can be imparted to the pipe 30.

The wall thickness T ₃₀ of the pipe 30 is appropriately determined according to the use of the pipe 30, and is preferably 2 to 30 mm, more preferably 3 to 20 mm, still more preferably 4 to 15 mm, for example. When the wall thickness T ₃₀ of the pipe 30 is at least the above lower limit value, the strength of the pipe 30 can be further increased. When the wall thickness T ₃₀ of the pipe 30 is not more than the above upper limit value, the joint strength with the multilayer joint 1 can be further increased.

The wall thickness T ₃₁ of the pipe inner layer 31 is appropriately determined according to the use of the pipe 30, and is, for example, preferably 1 to 15 mm, more preferably 2 to 12 mm, still more preferably 3 to 10 mm. When the wall thickness T ₃₁ of the pipe inner layer 31 is at least the above lower limit value, it is easy to impart various functions to the pipe inner layer 31. When the wall thickness T ₃₁ of the pipe inner layer 31 is not more than the above upper limit value, it is easy to impart various functions to the pipe outer layer 32.

The wall thickness T ₃₂ of the pipe outer layer 32 is appropriately determined according to the use of the pipe 30, and is, for example, preferably 1 to 20 mm, more preferably 2 to 15 mm, still more preferably 3 to 10 mm. When the wall thickness T ₃₂ of the pipe outer layer 32 is at least the above lower limit value, it is easy to impart various functions to the pipe outer layer 32. When the wall thickness T ₃₂ of the pipe outer layer 32 is not more than the above upper limit value, it is easy to impart various functions to the pipe inner layer 31.

Examples of the resin forming the pipe inner layer 31 include a fluorine-based resin, a polyphenylsulfone-based resin, a polyphenylene sulfide-based resin, and an olefin-based resin. When the pipe inner layer 31 is made of these resins, the pipe 30 is excellent in impact resistance and chemical resistance.
Examples of the resin forming the pipe outer layer 32 include vinyl chloride resin. When the resin forming the pipe outer layer 32 is a vinyl chloride resin, it is easy to join with the multi-layer joint receiving member 20 that comes into contact with the resin. Therefore, the water stopping property of the piping system 100 can be further improved.

The end face of the pipe 30 comes into contact with the annular portion 23. At this time, the end face of the pipe inner layer 31 and the joint body 10 come into contact with each other. Further, the pipe outer layer 32 and the receiving member 20 come into contact with each other. The pipe inner layer 31 and the joint body 10 are made of the same type of resin. Further, the pipe outer layer 32 and the multi-layer joint receiving member 20 are made of the same type of resin. Therefore, it is difficult to form a gap between the end surface of the pipe 30 and the multilayer joint 1, and it is possible to suppress the intrusion of water flowing through the flow path 15. As a result, the water stopping property of the piping system 100 can be further enhanced.

The multi-layer joint receiving member 20 of the present embodiment has an annular portion 23 projecting inward from one open end 22a of the body portion 21. A water-stopping convex portion 24 or a water-stopping concave portion 25 is formed on the outer surface of the annular portion 23. Therefore, the water-stopping protrusion 24 bites into the main body resin, and the main body resin enters the water-stopping recess 25, so that the water flowing through the flow path 15 can be stopped. As a result, the water stopping property of the multilayer joint 1 can be further enhanced.
In the multi-layer joint receiving member 20 of the present embodiment, two or more fitting convex portions 26 and fitting concave portions 27 are formed on the outer surface of the body portion 21. Therefore, the adhesive force between the multi-layer joint receiving member 20 and the main body resin can be further enhanced. As a result, the water stopping property of the multilayer joint 1 can be further enhanced.
The multi-layer joint receiving member ₂₀ of the present embodiment is fitted on the annular portion 23 side of the midpoint M of the length L20 in the pipe axis O2 direction of the body portion 21 and closest to the annular portion 23. A gate mark G is provided on the other open end 22b side of the body portion 21 with respect to the fitting convex portion 26a closest to the concave portion 27a or the annular portion 23. Therefore, the weld line of the multi-layer joint receiving member 20 is formed on the side of the other open end 22b of the body portion 21 away from the boundary between the annular portion 23 and the main body resin. As a result, it is difficult to form a gap at the boundary between the annular portion 23 and the main body resin, and the water blocking property of the multilayer joint 1 can be further enhanced.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the configuration is changed, combined, or deleted without departing from the gist of the present invention. Etc. are also included.
In the above-described embodiment, two or more fitting convex portions 26 and fitting concave portions 27 are formed on the outer surface of the body portion 21 of the multi-layer joint receiving member 20. However, the present invention is not limited to this, and the fitting convex portion or the fitting concave portion formed on the outer surface of the body portion may be one. From the viewpoint of further enhancing the adhesive force between the multi-layer joint receiving member and the main body resin, it is preferable that the number of fitting protrusions or fitting recesses formed on the outer surface of the body portion is two or more.
In the above-described embodiment, the gate mark G is formed in the fitting recess. However, the present invention is not limited to this, and the gate mark G may be formed on the fitting convex portion. Since it is difficult for a water path to be formed at the interface between the multi-layer joint receiving member and the main body resin, it is preferable that the gate mark G is formed in the fitting recess.
In the above-described embodiment, a straight pipe (socket) has been described as a multi-layer joint. However, the present invention is not limited to this, and the multi-layer joint may be a curved pipe (elbow), a T-shaped pipe (cheese), a Y-shaped pipe, or a joint having four or more openings. good.

1,1b Multi-layer joint 10 Joint body 11A, 11B Joint body opening 12A, 12B Receptacle 13A, 13B Step 14A, 14B Receptacle opening 15 Flow path 16A, 16B Receptacle outer layer 17A, 17B Layers 20, 20a, 20b, 20c Receptacle member for multi-layer joint 21 Body part 22a One open end 22b The other open end 23 Circular part 24 Water stop convex part 25 Water stop recess 26, 26a, 26b, 26c, 26d Fitting Joint convex part 27, 27a, 27b, 27c, 27d Fitting recess 30 Piping 31 Piping inner layer 32 Piping outer layer 100, 100b Piping system O1, O2 Pipe shaft M Midpoint G, G1, of the length of the body in the pipe axis direction G2, G3 Gate mark F Flow direction of the resin composition of the main body resin F1, F2a, F2b, F3 Flow direction of the first resin composition

Claims (5)

It has a cylindrical body and an annulus that projects inward from one open end of the body.
A water-stopping convex portion or a water-stopping concave portion is formed on the outer surface of the annular portion.
One or two or more fitting protrusions or fitting recesses are formed on the outer surface of the body portion.
The body is closer to the fitting protrusion or the ring, which is closer to the ring and is closer to the ring than the midpoint of the length of the body in the tube axis direction. A receiving member for a multi-layer joint in which a gate mark is formed on the other open end side of the body portion of the fitting recess. It is formed of a resin containing at least one selected from a hard vinyl chloride resin, an ABS (acrylonitrile-butadiene-styrene copolymer) resin, an acrylic resin, a polycarbonate resin, a polyethylene terephthalate resin, and a urethane resin. The receiving member for a multi-layer joint according to claim 1. It has a tubular joint body having a flow path inside and two or more receiving portions surrounding the opening of the joint body.
The main body resin forming the joint main body forms the receiving outer layer of the receiving portion, and the main body resin forms the receiving outer layer.
A multi-layer joint in which the multi-layer joint receiving member according to claim 1 or 2 forms an inner layer of the receiving portion of the receiving portion. The multilayer joint according to claim 3, wherein the main body resin contains one or more selected from a fluororesin, a polyphenylsulfone resin, a polyphenylene sulfide resin, and an olefin resin. The multi-layer joint according to claim 3 or 4,
A piping system including a piping arranged inside the receiving portion.
The pipe has at least an inner layer of the pipe facing the flow path and an outer layer of the pipe located on the outer surface.
The inner layer of the pipe is formed of a resin containing at least one selected from a fluororesin, a polyphenylsulfone resin, a polyphenylene sulfide resin, and an olefin resin.
The pipe outer layer contains a vinyl chloride resin and contains
A piping system in which the end surface of the pipe is in contact with the annular portion and the outer layer of the pipe is in contact with the inner surface of the receiving member for a multi-layer joint.

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